But it does not stop at your information. Who you call, what financial transactions you may have, location information, tracker cookies (to track all web movement), use logs and even your contacts lists are fair game.
That information will be available to all Facebook companies. Apart from providing the service, the new rules allow its use for
Legal measures including verifying accounts
Marketing Facebook company services
Provide third-party service providers to conduct surveys and research
The reality is that It will be easier for Facebook to link you to products and ads and to personalise features and content. It will also be easier to link you with people and groups of your interest, or you might know.
WhatsApp T&Cs state
To operate and provide our Services, you grant WhatsApp a worldwide, non-exclusive, royalty-free, sublicensable, and transferable license to use, reproduce, distribute, create derivative works of, display, and perform the information (including the content) that you upload, submit, store, send, or receive on or through our Services.
In the end, it is all about making Facebook more a part of your life by providing a range of free services in return for using your personal information for Facebook purposes.
The Free Software Foundation recommends that if you want any privacy, especially if you use the service for business or trade secrets, the following are secure alternatives. And if they offer a paid version go for it after you are happy with the trial.
iMessage (Apple users)
Signal and Telegram
But be careful – there are dozens of free chat apps that are just data harvesting. Read their privacy policies if steeping outside the recommended ones. Avoid WeChat or those Chinese apps with clouds hosted there.